1. Field of the Invention
The present invention relates to an encapsulated droplet, in particular, to a microfluidic system and a method for creating an encapsulated droplet with a removable shell.
2. Description of Related Art
The microfluidic system, which is also called the microfluidic chip, now is widely studied and highly valued. It has many advantages, such as, high response rate, high sensitivity, high reproducibility, low cost, and low pollution, so as to be applied to biology, medicine, optoelectronics and other fields.
For the latest technology of the droplet-based microfluidic system, the volume of the driven droplet has been decreased to the level of sub-micro liter, or even to the level of pico liter. The rapid evaporation is consequently an issue to the shrunk droplets.
Then, possible solutions to this rapid-evaporation issue include enhancement of packaging and sealing of the microfluidic system or precise control of the environmental humidity and temperature. However, the straight forward solutions may increase the systems cost or limit the applicable situations and environments.
Therefore, some scholars have proposed the concept of encapsulated droplet by encapsulating the original ease-of-evaporating droplet with another immiscible droplet. For example, the original one is a water droplet; the immiscible one is an oil droplet. The oil droplet will wrap all around the water droplet in order to form an oil shell, preventing the water drop from evaporation. However, making the oil-shell with a controlled and reproducible volume by manually dispensing is difficult.